The present invention generally concerns agricultural tractors and more particularly pertains to improved multi-purpose horticultural crop tractors. Furthermore, various present features separately pertain to improved hitching systems, movable operator stations, rear loader materials handling systems, and uses of a multipurpose tractor reversibly outfitted with implements adapted for irrigation or the like.
Present schemes and methodologies of production for a wide variety of vegetables typically make use of conventional farm tractors and various farming implements therefor, such as in conjunction with performance of hand-harvesting methods or operation of harvest-aids or fully mechanical harvesters. Basic conventional agricultural tractors have generally remained little changed since their initial introduction about the turn of this century. Even with the introduction of certain modern improvements, e.g., the three-point hitch, modern hydraulic systems, and advanced operator cabs with protection from roll-over, noise, and chemicals, conventional farm tractors have numerous limitations that prevent or reduce the chances for optimization of field operations. Many desirable features are typically lacking.
For example, there is often a lack of sufficient clearance to permit conduct of critical field operations (up to and including harvesting) for tall growing crops, such as sweet corn, staked tomatoes, peppers, and okra. Furthermore, conventional tractors typically lack the combined clearance and implement mounting features which would be desirable for intensive horticultural crops, such as vegetables, small tree crops, berries, and ornamentals.
Still another area of deficiency which has not been heretofore significantly addressed is the position and/or orientation of an operator's station, i.e., where the driver sits on the tractor and how he or she faces relative movement of the tractor and ongoing operations. Though implements have been introduced which ostensibly permit precision planting and cultivation, little in connection with the operator position has changed relative to monitoring and controlling such important operations. In short, the position of the operator station for typical present-day tractors severely limits operator visibility of various critical operations, such as precision planting, transplanting, cultivating, and mechanical harvesting. The typical fixed or nonmovable condition of most operator stations is also a drawback or limitation to maximum flexibility of prior so-called multipurpose tractors.
Yet another entirely separate area of consideration relates to the random traffic patterns of conventional tractors and field operations, particularly as relating to multicrop schemes. Some research studies have shown that such random traffic patterns can cause severe soil compaction in certain types of soils, resulting in reduced yields and increased energy requirements for deep tillage in order to overcome the machine induced compaction. Many conventional tractor designs are not adequately versatile and adaptable for accomplishing multiple purposes so as to timely allow for relatively time-important operations such as spraying and harvesting/field packing under wet soil conditions.
As counterpoint to random traffic patterns, controlled traffic production methods are being introduced which permanently designate crop-growing zones and traffic lanes for field crops. Compaction is therefore regulated to assure minimum compaction in the crop root zone, limited compaction in the seedling emergence area, and maximum compaction in the traffic lanes. While controlled traffic production methods offer the potential for eliminating heavy tillage needs in the crop production zone while simultaneously increasing compaction in traffic lanes over the years to improve tractor efficiency, flotation, and timeliness of critical operations, a typical conventional farm tractor by itself (though combined with various implements) is generally not versatile enough to efficiently support such controlled traffic production methodology.
Some vehicles exist today which exhibit high clearance characteristics as well as a three meter wheel width (twice the width of typical 1.5 meter-spaced crop rows so as to simultaneously span two rows). One example of such is the "GENERATION III" line of tobacco combines made by Powell Manufacturing Company, Inc., of Bennettsville, S.C. 29512. Another example of a high clearance machine is the 4400 "Hi-Trac" tobacco machine of Powell Manufacturing, while yet another example is the 4410 "Hi-Trac" high clearance sprayer of Powell Manufacturing Company.
Ford New Holland, Inc., of New Holland, Pa., markets a so-called bidirectional tractor referred to as the "VERSATILE 276."The tractor has a turning assembly, by which the seat, steering wheel, and console gauges all revolve 180 degrees as a unit, all contained within an operator station or cab. Throttle and other controls do not move with the seat and steering wheel, but are fixed within the operator station or cab, which results in the position of the throttle "changing sides" relative the operator as the operator reverses. In other words, the operator must relearn the control positions each time the seat and steering wheel are moved anywhere within the permitted 180 degrees of revolution. U.S. Pat. No. 3,721,077, by van der Lely, discloses a tractor having a driver's platform which is movable relative to the tractor frame to permit various implement attachments to be placed on an upper surface of the tractor. As variously shown, a driver's cabin which includes controls for the various tractor members and for steering, may be vertically adjusted and repositioned by movement of arms which are secured for pivoting about a generally horizontal axis. Falcone et al. (U.S. Pat. No. 3,841,429) discloses a vehicle such as a straddle carrier which has a driver's cab slidably received on top of a frame structure. The cab is preferably mounted on rails and the seat within the cab is rotatable.
Other known self-propelled vehicles or tractors have hitch arrangements which are variously adjustable. Examples of such are Bagno (U.S. Pat. No. 3,570,614); van der Lely (U.S. Pat. Nos. 4,648,472; 4,576,394; and 4,585,084); and Tatianko et al. (U.S. Pat. No. 3,664,431). While some of such exemplary patents disclose front and rear attachments for dual implement use, the illustrated tractors are generally not suitable for meeting high crop clearance requirements, and their implement interface versatility is generally too limited to provide a multipurpose tractor capable of efficiently performing varying desired operations.
One example of a self-powered agricultural implement adapted for use with relatively tall crops such as corn is Finley (U.S. Pat. No. 2,504,403). With the Finley construction, a large three-wheeled configuration is provided in which the operator sits high atop the overall framework, generally similar to operator seating for the high clearance machinery "Hi-Trac" Models 4400 and 4410 by Powell Manufacturing, as well as for van der Lely (U.S. Pat. No. 3,721,077) and Falcone et al. (U.S. Pat. No. 3,841,429), all referenced above. Finley incorporates a direct chain drive to the front of his three-wheel arrangement.
Other prior arrangements of general background interests are Johnson et al. (U.S. Pat. No. 2,513,942); Claas et al. (U.S. Pat. No. 2,888,088); Ashton et al. (U.S. Pat. No. 3,324,635); Ashton et al. (U.S. Pat. No. 3,324,637); Stott et al. (U.S. Pat. No. 3,425,194); and Doyen et al. (U.S. Pat. No. 4,632,200).